Wired casing

ABSTRACT

The present invention involves a method and apparatus for monitoring conditions downhole and/or manipulating downhole tools by placing electrical wire on a casing string while drilling with casing. Wire is inserted into a groove within the casing string while drilling with the casing string into a formation. The wire connects downhole equipment to surface equipment. Multiple casing strings may be drilled into the formation while wire is simultaneously inserted into a groove therein.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention generally relates to a method and apparatus for monitoring conditions downhole and/or manipulating downhole tools. More particularly, the present invention relates to a method and apparatus for monitoring conditions downhole and/or manipulating downhole tools while placing wire which connects the surface to downhole onto a casing string while drilling with casing. Even more particularly, the present invention relates to a method and apparatus for wiring casing while drilling with casing.

[0003] 2. Description of the Related Art

[0004] In conventional well completion operations, a wellbore is formed to access hydrocarbon-bearing formations by the use of drilling. In drilling operations, a drilling rig is supported by the subterranean formation. A rig floor of the drilling rig is the surface from which casing strings, cutting structures, and other supplies are lowered to form a subterranean wellbore lined with casing. A hole is formed in a portion of the rig floor above the desired location of the wellbore. The axis that runs through the center of the hole formed in the rig floor is well center.

[0005] Drilling is accomplished by utilizing a drill bit that is mounted on the end of a drill support member, commonly known as a drill string. The drill string includes sections of drill pipe threadedly connected to one another, often connected at the drilling rig by a pipe handling operation. To drill within the wellbore to a predetermined depth, the drill string is often rotated by a top drive or rotary table on the drilling rig. After drilling to a predetermined depth, the drill string and drill bit are removed and a section of casing is lowered into the wellbore.

[0006] Often, it is necessary to conduct a pipe handling operation to connect sections of casing to form a casing string which extends to the drilled depth. Pipe handling operations require the connection of a first casing section to a second casing section to line the wellbore with casing. To threadedly connect the casing strings, each casing section must be retrieved from its original location, typically on a rack beside the drilling platform, and be suspended above well center so that each casing section is in line with the casing section previously disposed within the wellbore. The threaded connection must be made up by a device that imparts torque to one casing section relative to the other, such as a power tong or a top drive. The casing string formed of the two casing sections is then lowered into the previously drilled wellbore.

[0007] Technology is available which allows communication in real time between the surface of the wellbore and within the wellbore while drilling with the drill string, often termed “measurements while drilling”. One data transmission method from downhole to the surface while drilling with the drill string is mud pulsing, which involves digitally encoding data and transmitting the data to the surface as pressure pulses in the mud system. Communication between the surface and downhole permits sensing of conditions within the wellbore, such as pressure, formation, temperature, or drilling fluid parameters. By monitoring the conditions within the wellbore in real time while drilling with the drill string, conditions may be adjusted and optimized accordingly. The mud pulsing method of data transmission is disadvantageously slow and capable of transmitting little or no power or data.

[0008] Another method for data transmission in real time through drill pipe while drilling with the drill string involves drilling with wires or cables. Employing wires or cables which connect surface equipment and downhole equipment located within the wellbore allows operation of downhole equipment by sending signals or power from the surface to downhole equipment. Exemplary downhole equipment which may be advantageously operated from the surface includes a motor which provides torque to the drill string for drilling into the formation as well as float equipment. Furthermore, communication between the surface and downhole allows sensing of wellbore conditions, as delineated above. A sensor may be placed close to or within the drill bit at the end of the drill string to transmit data regarding conditions present in the wellbore to the surface equipment. The surface equipment then processes the signal into interpretable data.

[0009] It is common to employ more than one string of casing in a wellbore. In this respect, the well is drilled to a first designated depth with a drill bit on a drill string. The drill string is removed. Sections of casing are connected to one another and lowered into the wellbore using the pipe handling operation described above to form a first string of casing longitudinally fixed in the drilled out portion of the wellbore. While the above method of data and power transmission in real time while initially drilling with the drill string to drill a hole for the casing string is generally more effective than mud pulsing because it allows more power and data transmission in a faster period of time, the process of drilling into the formation with the drill string to a first depth to form a wellbore for a first casing string while sensing conditions in real time, then removing the drill string from the wellbore, then placing the first casing string within the wellbore, then drilling the wellbore to a second depth with the drill string, then removing the drill string, then placing the second casing string within the wellbore, and then repeating this process for subsequent casing string is time consuming and, thus, not cost effective.

[0010] It is often desirable to monitor conditions within the wellbore or to operate tools disposed on the casing string while lowering the first casing string and/or subsequent casing strings into the wellbore. To communicate from the surface to downhole, and vice versa, a first section of wire is often connected to downhole equipment, while a second section of wire is connected to surface equipment. The first section of wire is disposed on the first casing section of the first casing string, while the second section of wire is disposed on the second casing section of the first casing string. The wires must be aligned to provide a conductive path between the surface and downhole. The usual method to align the wires of casing sections involves timing threads, wherein the threads of each casing section are machined so that at a given torque, the wires are aligned. Timing marks are usually disposed on each casing section. When the timing marks are aligned, which may be visually ascertained, the wire sections are aligned to conduct through casing sections. Methods for clocking or timing threads are described in U.S. Pat. No. 5,233,742 entitled “Method and Apparatus for Controlling Tubular Connection Make-Up”, issued on Aug. 10, 1993 to Gray et al., and in U.S. Pat. No. 4,962,579 entitled “Torque Position Make-Up of Tubular Connections”, issued Oct. 16, 1990 to Moyer et al., which are both herein incorporated by reference in their entirety.

[0011] The next step in a typical drilling operation includes cementing the first string of casing into place within the wellbore by a cementing operation. Next, the well is drilled to a second designated depth through the first casing string, and a second, smaller diameter string of casing comprising casing sections is hung off of the first string of casing. A second cementing operation is performed to set the second string of casing within the wellbore. This process is typically repeated with additional casing strings until the well has been drilled to total depth. In this manner, wellbores are typically formed with two or more strings of casing.

[0012] After the two or more strings of casing are set within the wellbore, it is often desirable to monitor conditions within the wellbore during operations such as hydrocarbon production operations or treatment operations. It is also desirable to operate downhole tools such as packers and valves from the surface during downhole operations. One method of providing communication from the surface to downhole (and vice versa) involves running wire connected to downhole equipment at one end, such as a sensor or a downhole tool, and connected to surface equipment at the other end, such as a processing unit, into the wellbore after placing the casing string into the wellbore. Another method involves placing a section of wire on each casing string as it is lowered into the previously-drilled wellbore, then inductively coupling the wire from each casing string to the wire from the adjacent casing string. In this way, the casing strings may be inductively coupled end-to-end. A method and apparatus for inductively coupling casing strings is illustrated in U.S. Pat. No. 4,901,069 issued to Veneruso on Feb. 13, 1990, which is herein incorporated by reference in its entirety.

[0013] In the conventional well completion operations described above, wire is placed on the outside of a casing section as it is lowered into the drilled out portion of the formation. Running the wire on the outside of casing sections subjects the wire to damage and degradation due to wellbore fluids, which may be turbulent in flow and/or high in temperature within the wellbore.

[0014] As an alternative to the conventional drilling method, drilling with casing is a method often used to place casing strings within the wellbore. This method involves attaching an earth removal member typically in the form of a drill bit to the lower end of the same string of casing which will line the wellbore. Drilling with casing is often the preferred method of well completion because only one run-in of the working string into the wellbore is necessary to form and line the wellbore for each casing string.

[0015] Drilling with casing may be accomplished in at least two manners. In the first method, the first casing string inserted into the wellbore has an earth removal member operatively attached to its lower end. The first casing string may include one or more sections of casing threadedly connected to one another by the pipe handling operation described above. In a drilling with casing operation, the casing sections are threaded to one another using the top drive connected to a gripping head. The gripping head has a bore therethrough through which fluid may flow and grippingly engages the casing sections to serve as a load path to transmit the full torque applied from the top drive to the casing sections to make up the connection between casing sections. The gripping head is an external gripping device such as a torque head or an internal gripping device such as a spear. An exemplary torque head is described in U.S. Pat. No. 6,311,792 B1 issued to Scott et al. on Nov. 6, 2001, which is herein incorporated by reference in its entirety. An exemplary spear is described in U.S. Patent Application Publication Number US 2001/0042625 A1, filed by Appleton on Jul. 30, 2001, which is herein incorporated by reference in its entirety.

[0016] After the pipe handling operation is conducted to connect casing sections to form a casing string, the first casing string is lowered into the formation while the earth removal member rotates to drill the first casing string to a first depth. The first casing string is then secured above the formation by a gripping mechanism such as a spider, which comprises a bowl inserted in the rig floor and gripping members such as slips which are movable within the bowl along an inclined slope to grippingly engage the outer diameter of casing strings. The gripping head is released from engagement with the first casing string.

[0017] The gripping head then grippingly and sealingly engages a second casing string. The second casing string is threadedly connected to the first casing string by a pipe handling operation. The spider is released as the gripping head now suspends the two connected casing strings, and the earth removal member on the first casing string is rotated while the first and second casing strings, which are now connected and move together, are lowered to drill the first and second casing strings to a second depth within the formation. This process is repeated to drill subsequent casing strings to a further depth within the formation.

[0018] A second drilling with casing method involves drilling with concentric strings of casing. In this method, the first casing string is run into the wellbore with a first earth removal member operatively connected to its lower end. The first earth removal member rotates relative to the first casing string as the first casing string is simultaneously lowered into the formation to drill the first casing string to a first depth. The first casing string is set by setting fluid such as cement within the wellbore. Next, a second casing string, which is smaller in diameter than the first casing string, having a second earth removal member operatively connected to its lower end, drills through the cutting structure of the first casing string and to a second depth in the formation. The second earth removal member and the second casing string drill in the same way as the first casing string. The second casing string is set within the wellbore, and subsequent casing strings with earth removal members attached thereto are drilled into the formation in the same manner as the first and second casing strings.

[0019] During the drilling with casing operation, it is necessary to circulate drilling fluid while drilling the casing string into the formation to form a path within the formation through which the casing string may travel. Failure to circulate drilling fluid while running the casing string into the formation may cause the casing string to collapse due to high pressure within the wellbore; therefore, it is necessary for a fluid circulation path to exist through the casing string being drilled into the formation. A unique condition encountered while drilling with casing is plastering. Because the casing string is rotated so close to the formation, less fluid exists around the outside of the casing string while drilling.

[0020] In both drilling with casing methods described above, after the casing string is drilled to the desired depth within the formation, the casing string must often be cemented into the wellbore at a certain depth before an additional casing string is hung off of the casing string so that the formation does not collapse onto the casing string due to lack of support. Furthermore, the casing string must be cemented into the formation once it reaches a certain depth to restrict fluid movement between formations. To cement the casing string within the wellbore, a cementing tool including a cementing head is inserted into the casing string to inject cement and other fluids downhole and to release cement plugs.

[0021] While drilling with casing, it is desirable to monitor parameters within the wellbore in real time, as well as to operate downhole tools while drilling. It would be especially advantageous to sense the extent of plastering and hydrostatic conditions in real time while drilling with casing, as the solids content of the drilling fluid and other parameters of the fluid may be monitored and optimized while the casing string is drilling to facilitate drilling the casing string into the formation. It would be further advantageous to monitor downhole tools in real time, including cementing equipment and mud motors used to rotate the casing string while drilling.

[0022] To provide communication between the surface and downhole to monitor downhole conditions and operate downhole tools, the data communication must exist through a wire connecting the surface to downhole. Currently in drilling with casing operations, the wire is run into the wellbore after insertion of all of the desired casing strings within the wellbore. Downhole equipment is run into the wellbore with the casing string, and then, after the casing string is placed within the wellbore, a wire connected at one end to surface equipment is run into the wellbore and plugged into the downhole equipment. Running the wire into the casing string after drilling the casing string into the formation does not allow real time monitoring of the wellbore conditions during drilling.

[0023] Therefore, it is desirable to produce a wired casing string which is capable of transmitting electricity through the casing string across the threadable connections of individual casing joints. It is further desirable to produce a casing string which is capable of drilling into the formation as well as cementing the casing string into the formation through communication to the downhole equipment from the surface. It is even more desirable to place wire on the casing string while drilling with the casing string into the formation to allow real time monitoring of downhole conditions and operation of downhole tools while drilling with casing. It is further desirable to protect the wire from damage within the wellbore. It is even further desirable to protect the wire from damage within the wellbore across connections of sections of casing.

SUMMARY OF THE INVENTION

[0024] The present invention generally relates to lowering casing while simultaneously placing wire on the casing. In one aspect, the present invention involves lowering a first casing string with an earth removal member operatively connected to its lower end into an earth formation and placing wire on the first casing string while lowering the first casing string. A second casing string may be connected to the first casing string, then the first casing string lowered while placing wire on the second casing string.

[0025] Another aspect of the present invention involves a method of wiring casing while drilling with casing comprising lowering a first casing string with an earth removal member operatively connected to its lower end into an earth formation, placing a first wire on the first casing string while lowering the first casing string to a first depth within the formation, lowering a second casing string with an earth removal member operatively connected to its lower end into the formation, and placing a second wire on the second casing string while lowering the second casing string to a second depth within the formation. Yet another aspect of the present invention involves an apparatus comprising downhole equipment for sensing information from within the wellbore, surface equipment for processing the information, a wire for transmitting the information from the downhole equipment to the surface equipment, and a casing string with an earth removal member operatively connected to its lower end, wherein the casing string houses the wire.

[0026] Another aspect of the present invention includes an apparatus for use in transmitting signals from within a wellbore to a surface of the wellbore comprising downhole equipment for sensing information from within the wellbore, surface equipment for processing the information, a wire for transmitting the information from the downhole equipment to the surface equipment, and a first casing section comprising a groove therein for at least partially subflushing the wire to the surface of the first casing section. A method for monitoring conditions within a wellbore by wiring casing is also provided, comprising lowering a first casing section to a first depth within a formation and placing wire on the first casing section while lowering the first casing section, wherein the wire is at least partially sub-flushed to a surface of the first casing section.

[0027] Yet another aspect includes an apparatus for use in transmitting signals from within a wellbore to a surface of the wellbore, comprising downhole equipment for sensing information from within the wellbore, surface equipment for processing the information, a wire for transmitting the information from the downhole equipment to the surface equipment, a first tubular comprising a groove therein for at least partially subflushing the wire to a surface of the first tubular, and a second tubular comprising a groove therein for at least partially subflushing the wire to a surface of the second tubular, wherein the first tubular is connected to the second tubular and the wire is subflushed across the connection. Also included is a method for monitoring conditions within a wellbore while lowering tubulars into the wellbore, comprising lowering a first tubular into the wellbore, placing wire on the first tubular while lowering the first tubular, wherein the wire is at least partially sub-flushed to a surface of the first tubular, connecting the first tubular to a second tubular, lowering the second tubular into the wellbore, and placing wire on the second tubular while lowering the second tubular wherein the wire is at least partially sub-flushed to a surface of the second tubular, wherein the wire is subflushed across the connection of the first tubular to the second tubular.

[0028] The method and apparatus of the present invention allow sensing and optimization of downhole conditions in real time while lowering casing, as well as operation of downhole tools in real time while drilling with casing. Moreover, placing wire on the casing string while lowering casing permits operation of automated devices downhole while the casing string is penetrating the formation as well as after the casing string is placed into the formation. The present invention further allows protection of wires while lowering the casing and after the casing is placed within the wellbore or drilled into the wellbore.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

[0030]FIG. 1 is a sectional view of a first casing string connected to a first casing coupling being lowered into a hole in a rig floor at well center.

[0031]FIG. 2 is a section view of the first casing string and first casing coupling of FIG. 1.

[0032]FIG. 2A is a downward view of the first casing string along line 2A-2A of FIG. 1.

[0033]FIG. 2B is a downward view of the first casing string , wherein a tapered groove of the first casing string houses a wire therein.

[0034]FIG. 3 is a sectional view of the first casing string of FIG. 1. A wire connects downhole equipment located near an earth removal member of the first casing string to surface equipment located at the surface.

[0035]FIG. 4 is a sectional view of the first casing string of FIG. 1 drilling into a formation. The wire is located within a groove on the first casing string as the first casing string is drilled into the formation.

[0036]FIG. 5 is a sectional view of the first casing string drilled into the formation to a first depth and held by a spider. A second casing string is held above the first casing coupling by a gripping head.

[0037]FIG. 6 is a sectional view of the second casing string threaded onto the first casing coupling. A groove of the first casing coupling is aligned with a groove on the second casing string by timing threads.

[0038]FIG. 7 is a sectional view of the second casing string and the first casing string being drilled into the formation to a second depth, while the wire is simultaneously dispensed into the groove of the second casing string.

[0039]FIG. 8 is a cross-sectional view of an alternate embodiment of the present invention. A first casing string has an earth removal member operatively attached to its lower end and is being drilled into a formation. A wire connects downhole equipment located near an earth removal member of the first casing string to surface equipment. The wire is located within a groove on the first casing string as the first casing string is drilled into the formation.

[0040]FIG. 9 is a cross-sectional view of the first casing string of FIG. 8, where the earth removal member of the first casing string is being drilled through by a second casing string with an earth removal member operatively attached to its lower end. The second casing string has wire located within a groove as the second casing string is drilled into the formation.

[0041]FIG. 10 is a cross-sectional view of the first casing string and second casing string of FIG. 9 set at a depth within the formation. The wires are inductively coupled to communicate from surface equipment to downhole equipment.

[0042]FIG. 11 is a sectional view of an alternate embodiment of the present invention. A wire is placed in a groove in a first casing string above a rig floor of a drilling rig.

[0043]FIG. 12 is a downward view of the first casing string of FIG. 11 disposed within a spider. A gap is disposed between gripping members of the spider to allow passage of the wire therethrough.

[0044]FIG. 13 shows an embodiment of grooves disposed on casing strings and casing couplings which may be used with any of the embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0045]FIG. 1 shows a drilling rig 10 located above a surface 100 of a hydrocarbon-bearing formation 77. The drilling rig 10 supports a rig floor 20 above the surface 100. The rig floor 20 has a hole therethrough, the center longitudinal axis of which is termed well center. A spider 60 is disposed around or within the hole in the rig floor 20 to grippingly engage a first casing string 65, second casing string 30, and subsequent casing strings (represented by 15 of FIG. 5) at various stages of the operation. The spider 60 has gripping members such as slips (not shown) located therein to grippingly engage the casing strings 65, 30, and 15. A pipe handling arm (not shown) may extend from a side rail of the drilling rig 10 above the spider 60. The pipe handling arm is pivotable from a position perpendicular to the rig floor 20 when unactuated to a position parallel to the rig floor 20 when unactuated. Located on an end of the pipe handling arm closest to well center is a clamp (not shown) for engaging and guiding the casing strings 65, 30, and 15 at stages of the operation.

[0046] Connected to an upper portion of the drilling rig 10 is a draw works 105 with cables 75 which suspend a traveling block 35 above the rig floor 20. The traveling block 35 holds a top drive 50 above the rig floor 20. The top drive 50 includes a motor (not shown) which is used to rotate the casing strings 65, 30,15 relative to the rig floor 20 at various stages of the operation while drilling with casing or while making up or breaking out a threadable connection between the casing strings 65 and 30 and/or casing strings 30 and 15. The top drive 50 is moveable co-axially with the well center along a railing system (not shown). The railing system prevents the top drive 50 from rotational movement during rotation of casing strings 65, 30, and 15, creating the necessary torque for the casing strings 65, 30, 15 but at the same time allowing for vertical movement of the top drive 50 under the traveling block 35.

[0047] A gripping head 40 is connected, preferably threadedly connected, to a lower end of the top drive 50. As shown in FIG. 1, the gripping head 40 is a torque head which employs gripping members such as slips (not shown) within its inner diameter to engage the outer diameter of the casing strings 65, 30, 15. The slips may be actuable by hydraulic force. It is understood that the gripping head 40 may also include a gripping mechanism which has gripping members disposed on its outer diameter to engage the inner diameter of the casing strings 65, 30, 15, such as a spear (not shown). FIG. 1 shows the gripping head 40 grippingly and sealingly engaging an end of a first casing coupling 96. The gripping members within the gripping head 40 move inward along the inner wall of the gripping head to grip the outer diameter of the first casing coupling 96. In the alternative, the gripping members may engage the outer diameter of the first casing string 65 below the first casing coupling 96.

[0048] The lower end of the first casing coupling 96 is threadedly connected to an upper end of the first casing string 65. The first casing coupling 96 is a hollow, tubular-shaped device with female threads located on each of its ends to connect the first casing string 65 to second casing string 30 because the first casing string 65 has male threads at an upper end, and the second casing string 30 has male threads at both ends. Typically, subsequent casing strings 15 have male threads at both ends; therefore, a second casing coupling 31 is threadedly connected to an end of the second casing string 30, and likewise for subsequent casing strings 15. The casing couplings 96, 31 may be threaded onto the casing strings 65, 30 on location at the drilling rig 10 or prior to transporting the casing string 65, 30 to the drilling rig 10.

[0049] The first casing string 65 may include one or more joints or sections of casing threadedly connected to one another by one or more casing couplings. At a lower end of the first casing string 65 is an earth removal member, which may include a cutting structure 110 as shown in FIG. 1, for example a drill bit, which is used to drill through the formation 77 to form a wellbore 115 (see FIG. 3). The cutting structure 110 is operatively connected to the lower end of the first casing string 65, so that the connection between the cutting structure 110 and the first casing string 65 may exist anywhere within the first casing string 65, but the lower portion of the cutting structure 110 protrudes below the first casing string 65. The cutting structure 110 is rotatable in relation to the first casing string 65, as the cutting structure 110 rotates (by power produced by a mud motor, for example) while the first casing string 65 is lowered, without rotation of the casing string 65, to drill into the formation 77.

[0050] The second casing string 30 is shown located on a rack 101 away from the rig floor 20. The second casing string 30, which may also include one or more joints or sections of casing threadedly connected to one another by one or more casing couplings, is threadedly connected to the second casing coupling 31 at an end. The second casing string 30 does not have an earth removal member or cutting structure connected to its other end. Subsequent casing strings (such as 15) are similar to the second casing string 30 and second casing coupling 31.

[0051]FIG. 2 depicts the second casing string 30 and the second casing coupling 31. The second casing string 30 has a longitudinal groove 121 disposed therein. Likewise, the second casing coupling 31 has a longitudinal groove 122 disposed therein. The grooves 121 and 122 may be sub-flushed to the surface of the second casing string 30 and second casing coupling 31, respectively. The second casing string 30 and the second casing coupling 31 are threadedly connected so that the grooves 121, 122 are aligned with one another to form a continuous groove along the length of the second casing string 30 and the second casing coupling 31. The grooves 121, 122 are designed to receive and house a wire 140 (describe below, see FIG. 1). The groove 122 of the second casing coupling 31 slopes upward from the groove 121 of the second casing string 30, as the second casing coupling 31 is necessarily larger in diameter than the second casing string 30 so that the male threads of the second casing string 30 may be housed within the female threads of the second casing coupling 31. Accordingly, the wire 140 (see FIG. 1) ramps upward from the second casing string 30 to the second casing coupling 31 when disposed within the grooves 121, 122. A subsequent casing string 15 for threadable connection to the second casing coupling 31 will possess a smaller outer diameter than the second casing coupling 31; therefore, the wire 140 will ramp downward along the slope of the groove in the subsequent casing string 15. The same pattern results for each subsequent casing string (not shown) and casing coupling (not shown).

[0052] Referring again to FIG. 1, the first casing string 65 has a longitudinal groove 111 disposed therein, and the first casing coupling 96 has a longitudinal groove 112 disposed therein. The longitudinal grooves 111, 112 are the same as the longitudinal grooves 121, 122 in every respect except at the lower end of the first casing string 65, as the cutting structure 110 is located at the lower end of the first casing string 65 rather than a male thread for receiving a casing coupling. The longitudinal grooves 111, 112 may be aligned with one another either before or after they are located at the drilling rig 10.

[0053] Downhole equipment 170 is shown located above the cutting structure 110 on the first casing string 65. In the alternative, the downhole equipment 170 may be located within the cutting structure 110 or within any downhole tool located on or in the first casing string 65. The downhole equipment 170 may include any equipment for receiving signals from the surface 100 of the wellbore 115 for controlling downhole tools including but not limited to cutting structures, cementing apparatus, valves, and packers. The downhole equipment 170 may be used to power and operate the downhole tools while drilling into the formation 77. The present invention may be utilized during a drilling with casing operation with the cementing apparatus and methods for cementing casing strings into the formation described in co-pending U.S. patent application Ser. No. 10/259,214 entitled “Smart Cementing Systems,” filed on Sep. 27, 2002, which is herein incorporated by reference in its entirety.

[0054] Alternatively, the downhole equipment 170 may include devices for sensing and/or transmitting conditions within the wellbore 115. Downhole equipment 170 includes but is not limited to sensors which may be used with fiber optic cables. The downhole equipment 170 may be used to sense conditions in real time while drilling into the formation 77 with the first casing string 65. Specifically, the downhole equipment 170 may be utilized to sense plastering effects produced while drilling with casing.

[0055]FIG. 2A is a downward view along line 2A-2A of FIG. 1. In one embodiment, one or more wire clamps 130 are optionally disposed within or above the groove 111 and/or the groove 112 to hold the wire 140 within the grooves 111 and 112. FIG. 2A shows a wire clamp 130 disposed within the groove 111 of the first casing string 65. One or more wire clamps 130 may also optionally be located along the groove 121 and/or the groove 122 of the second casing string 30 and second casing coupling 31 to hold the wire 140 within the grooves 121 and 122 (see FIG. 7). Wire clamps 130 may be in the form of bands of metal, such as hose clamps, or of plug elastomers.

[0056]FIG. 2B shows an alternate embodiment of the groove 111 and/or groove 112. Instead of wire clamps 130, the upper ends 111 B and 112B of sides 11A and 112A of the grooves 111 and 112 may be designed to protrude inward so that the distance between the sides 111 A and 112A of the grooves 111 and 112 at the upper ends 111B and 112B (closest to the outer diameter of the casing string 65 or casing coupling 96) is smaller than the outer diameter of the wire 140. The ends 111C and 112C of the grooves 111 or 112 closer to the inner diameter of the casing string 65 or casing coupling 96 are larger than the upper ends 111B and 112B, so that the grooves 111 and 112 have a width large enough to fit the wire 140 therein. The sides 111A and 112A may be taped inward, as shown in FIG. 2B, from the ends 111C, 112C closest to the inner diameter to the ends 111B, 112B at the outer diameter of the casing string 65 or casing coupling 96. Thus, the wire 140 may be elastically compressed past the ends 111B and 112B into the grooves 111 and 112 and securely housed therein without the use of the wire clamp 130. Fast curing adhesives (not shown) may also be used to adhere the wire 140 to the grooves 111 and 112 as the wire 140 is placed within the grooves 111 and 112. The grooves 121 and 122 may be constructed in the same manner to avoid the use of clamps 130.

[0057] Surface equipment 180 is connected to an end of the wire 140. Surface equipment 180 includes but is not limited to a telemetry unit, processor, and/or display unit/user interface. The surface equipment 180 may perform the function of transmitting signals through the wire 140 to operate downhole tools or may receive and process or display downhole conditions through information gathered by downhole equipment 170 and ultimately transmitted through the wire 140 to the surface equipment 180.

[0058] The wire 140 is housed on a spool 183. The spool 183 is located below the rig floor 20 so that the wire 140 does not travel through the spider 60 while the wire 140 is dispensed from the spool 183, as the spider 60 has slip members which may damage the wire 140. As shown in FIG. 1, the spool 183 is located on the surface 100 of the formation 77, shown in FIG. 1 located on a rack 195. In the alternative, a second rig floor (not shown) may be built below the rig floor 20, and the wire 140 may be dispensed from the spool 183 placed on the second rig floor. The spool 183 has an axle 187 suspending the wire 140 above legs 186, while a dispensing unit 190 is used to dispense the wire 140 from the spool 183. The legs 186 remain stationary while the wire 140 is dispensed from around the axle 187, as described below. Slip rings (not shown), or circumferential conductive threads, may be used to conduct electricity through the spool 183 to the wire 140.

[0059] In the operation of the embodiments shown in FIGS. 1-7, the first casing string 65 is retrieved from the rack 101, a pickup/lay down machine (not shown), or another location away from well center. The first casing string 65 may be brought to well center from the rack 101 by an elevator (not shown), the gripping head 40, or any other gripping mechanism. The first casing string 65 with the first casing coupling 96 threadedly connected thereto is ultimately placed within the gripping head 40, and the gripping members of the gripping head 40 grippingly and sealingly engage the outer diameter of the first casing coupling 96 or the first casing string 65, as shown in FIG. 1. Alternatively, when internal gripping members are used, such as when using a spear as the gripping head 40, the gripping head 40 is placed inside the first casing string 65, and the gripping members grippingly and sealingly engage the inner diameter of the first casing string 65. In this position, fluid communication exists through a sealed path from the top drive 50 all the way down through the gripping head 40. The gripping head 40 also fixes the first casing string 65 longitudinally and rotationally with respect to the gripping head 40.

[0060] The pipe handling arm (not shown) is then pivoted out toward the first casing string 65 while the clamp (not shown) of the pipe handling arm is in an open position so that jaws (not shown) of the clamp are open. Once the clamp is positioned around the first casing string 65, the jaws of the clamp are closed around the first casing string 65. The first casing string 65 is moved downward toward the formation 77 by the cables 75 on the draw works 105.

[0061] Once the first casing string 65 is lowered to a location below the rig floor 20 but above the formation 77, the wire 140 is connected to the downhole equipment 170 so that signals may be sent and/or received through the wire 140 between the downhole equipment 170 and the surface equipment 180. As previously mentioned, the surface equipment 180 is connected to the opposite end of the wire 140 from the downhole equipment 170. FIG. 3 shows the end of the wire 140 connected to the downhole equipment 170.

[0062] Next, the wire 140 is placed within the groove 111 in the first casing string 65. The wire 140 may be secured within the groove 111 by the wire clamp 130, if one is provided within or on the groove 111. As the first casing string 65 is lowered further toward the formation 77, the wire 140 is continually threaded within the groove 111 so that the groove 111 houses the length of the wire 140 which is dispensed.

[0063] The cutting structure 110 of the first casing string 65 is then rotated, preferably by a mud motor, while the draw works 105 moves the first casing string 65 downward into the formation 77 to drill the first casing string 65 into the formation 77. The pipe handling arm aids in maintaining the first casing string 65 in line with well center to guide the first casing string 65 during the drilling operation. The cutting structure 110 drills into the formation 77 to form a wellbore 115. While drilling with the first casing string 65, drilling fluid under pressure is introduced into the assembly to prevent the inner diameter of the first casing string 65 from filling up with mud and other wellbore fluids, as well as to create a path for the first casing string 65 within the formation 77 while drilling. The sealable engagement of and the bores running through the top drive 50, gripping head 40, and the first casing string 65 allow fluid to circulate through the inner diameter of the first casing string 65, and up through an annular space between the first casing string 65 and the formation 77. As the first casing string 65 is drilled into the formation, the wire 140 is continually placed within the groove 111 in the first casing string 65 as the axle 187 of the spool 183 rotates to dispense the wire 140. The groove 111 serves as a housing to protect the wire 140 from wellbore fluids while the first casing string 65 is being drilled into the formation 77. FIG. 4 shows the first casing string 65 as it is being drilled into the formation 77 to form a wellbore 115.

[0064] Once the first casing string 65 is drilled to the desired depth within the formation 77, the spider 60 is actuated to grippingly engage the outer diameter of a portion of the first casing string 65. The gripping members (not shown) or slips of the spider 60 are engaged around the outer diameter of the casing string 65 to rotationally and axially fix the first casing string 65 relative to the rig floor 20. After the spider 60 is actuated to grip the first casing string 65, the gripping members of the gripping head 40 are released and the assembly is moved upward relative to the rig floor 20 and the first casing string 65 disposed therein. The pipe handling arm is then unactuated.

[0065] In the next step of the operation, the second casing string 30 and the connected second casing coupling 31 are retrieved from the rack 20 and brought to well center. The gripping head 40 grippingly and sealingly engages the second casing string 30 or the second casing coupling 31 and suspends the second casing string 30 and second casing coupling 31 above the rig floor 20. FIG. 5 shows the first casing string 65 drilled into the formation to a first depth and the second casing string 30 and second casing coupling 31 suspended above the rig floor 20 at well center.

[0066] Next, the pipe handling arm is again actuated so that the clamp is placed around the second casing string 30. Now the pipe handling operation involving threading the second casing string 30 onto the first casing string 65 is ready to be conducted. The second casing string 30 is lowered toward the first casing coupling 96 so that the female threads of the first casing coupling 96 contact the male threads of the second casing string 30. The motor (not shown) of the top drive 50 rotates the gripping head 40 and, thus, the second casing string 30. The second casing string 30 along with the second casing coupling 31 rotate relative to the first casing string 65 and the first casing coupling 96, which both remain axially and rotationally fixed within the rig floor 20.

[0067] The second casing string 30 is rotated to thread onto the first casing string 65 so that the threaded connection is made up to connect the casing strings 65, 30. In making up the threadable connection, the groove 112 of the first casing coupling 96 must be aligned with the groove 121 of the second casing string 30 so that the wire 140 may be housed within a continuous groove formed by the aligned grooves 112, 111, 122, and 121. In aligning the grooves 112 and 121, timing marks may be utilized to clock or time the threads. Timing marks or hatch marks (not shown) are placed on the casing string 30 and casing couplings 96 to be made up so that whether the adjacent casing strings 30 and 65 are properly aligned may be determined by visual inspection. Once the timing marks are aligned with one another, rotation of the second casing string 30 is halted and the grooves 112 and 121 are aligned with one another. The threads of the casing strings 65 and 30 and couplings 96 and 31 (as well as subsequent casing strings) are calculated and machined, typically in the factory, so that the timing marks indicate the rotational synchronization of the grooves 112 and 121 at a certain torque. FIG. 6 shows the groove 112 matched with the groove 121 by timing of the threads.

[0068] After making up the threadable connection between the casing strings 30 and 65, the drilling with casing operation begins. The gripping members of the spider 60 are released so that the first casing string 65 is movable axially within the formation 77. At this point, the gripping head 40 suspends both of the casing strings 65 and 30 because the second casing string 30 is connected to the first casing string 65. The draw works 105 lowers the casing string 65, 30 into the formation 77 while the cutting structure 110 is again rotated to drill to a second depth within the formation 77. Simultaneously, drilling fluid is introduced into the top drive 50 to flow through the gripping head 40 and through the second casing string 30 and the first casing string 65, then up through the annular space between the casing string 65, 30 and the formation 77. Also simultaneously, the wire 140 is dispensed from the spool 183 and inserted within the remainder of the groove 111, within the groove 112, then within the groove 121 as the casing string 65, 30 continues downward while drilling into the formation 77. FIG. 7 shows the casing string 65, 30 drilled to a second depth within the formation 77 to form a wellbore 115 of a second depth. The gripping members of the spider 60 are then engaged to contact the outer diameter of the second casing string 30, the gripping head 40 is released from the second casing string 30, and the operation is repeated for subsequent casing strings (such as 15).

[0069] Because the wire 140 is threaded onto the casing string 65, 30 while the casing string 65, 30 is drilling into the formation, the downhole equipment 170 may be manipulated and operated in real time by signals sent from the surface equipment 180 through the wire 140. For example, the earth removal member, valves, and/or packers may be operated by use of the present invention. Similarly, the downhole equipment 170 may sense wellbore conditions including geophysical parameters in real time while drilling and send signals from downhole to the surface equipment 180 for processing. After sensing parameters while drilling, the drilling conditions may be varied and optimized accordingly. Conditions which may be advantageously monitored and/or optimized include but are not limited to downhole pressure, temperature, and plastering effects caused during the drilling with casing operation.

[0070]FIGS. 8-10 depict an alternate embodiment of the present invention primarily for use while drilling with concentric strings of casing. Although not shown, the drilling rig 10 of FIGS. 1-7 with all of its component parts is located above the surface 100 in the embodiment of FIGS. 8-10. The same spool 183 with identical parts to the embodiment of FIGS. 1-7 dispenses the wire 140 into the groove 111 of the first casing string 65, as shown in FIGS. 8-10, in the same way as explained above in relation to FIGS. 1-7. As in FIGS. 1-7, the wire 140 is connected at one end to the surface equipment 180 and at the other end to downhole equipment 170. Also as in FIGS. 1-7, the first casing string 65 has a cutting structure 110 operatively connected to its lower end and powered by, for example, a mud motor. The first casing string 65 may optionally have a coupling (not shown) threadedly connected to its upper end. The casing string 65 may include one or more sections of casing threadedly connected by couplings.

[0071]FIGS. 9-10 show a second casing string 165 at various stages of drilling into the formation 77. The second casing string 165 may also optionally include one or more sections of casing threadedly connected by couplings. A coupling 396 is optionally threadedly connected to an upper end of the second casing string 165. The second casing string 165 has an earth removal member, preferably a cutting structure 210 such as a drill bit, operatively connected to its lower end and powered by another mud motor or other apparatus for providing torque to the cutting structure 210. The cutting structure 210 is used to drill through the cutting structure 110 of the first casing string 65 and through the portion of the formation 77 below the first casing string 65. Located on the second casing string 165 is downhole equipment 270, which is connected to a wire 240. The wire 240 is disposed within a groove 211 located within the second casing string 165, which is similar to the groove 111 of the first casing string 65. The coupling 396 of the second casing string 165 also has a groove 312 located therein for housing the wire 240. The wire 140 is dispensed from a spool 283 into the grooves 211 and 312 during the operation. The spool 283 has an axle 287 and dispensing apparatus 290 as described above in relation to FIGS. 1-7.

[0072] In the operation of the embodiment of FIGS. 8-10, the first casing string 65 is picked up from the rack 101 and moved to well center, and the gripping head 40 grippingly engages the first casing string 65. The wire 140 is connected to the downhole equipment 170 after the first casing string 65 is lowered by the cables 75 through the unactuated spider 60. The first casing string 65 is lowered while the cutting structure 110 is rotated in relation to the first casing string 65, and drilling fluid is simultaneously introduced through the top drive 50, gripping head 40, and first casing string 65. While drilling the first casing string 65 into the formation 77, the wire 140 is dispensed from the spool 183 into the groove 111 of the first casing string 65. As described above, the groove 111 may have a smaller inner diameter upper portion or may have clamps (not shown) which maintain the wire 140 within the groove 111. FIG. 8 shows the first casing string 65 being drilled into the formation 77 while simultaneously placing wire 140 within the groove 111.

[0073] As shown in FIG. 9, the first casing string 65 is drilled to a first depth and set within the wellbore 115 by setting fluid such as cement 300, which is cured to hydrostatic pressure. The second casing string 165 is then releasably engaged by a working string (not shown), which is grippingly and sealingly connected to the gripping head 40, and suspended above the first casing string 65 at well center. Next, the downhole equipment 270 of the second casing string 165 is connected to the wire 240. The second casing string 165 is lowered while simultaneously rotating the cutting structure 210 and circulating drilling fluid through the top drive 50, gripping head 40, working string, second casing string 165, and up through an annulus between the outer diameter of the second casing string 165 and the inner diameter of the first casing string 65. Wire 240 is simultaneously dispensed from the spool 283 and placed into the groove 211 of the second casing string 165, which may possess wire clamps (not shown) or a smaller upper portion, as described above in relation to the groove 111. When wire 240 is placed within the length of the groove 111, wire 240 is then placed into the groove 312 of the coupling 396. The cutting structure 210 drills through the cutting structure 110 of the first casing string 65, then to a second depth within the formation 77, as shown in FIG. 9.

[0074] When the cutting structure 210 is drilled to the desired second depth, the second casing string 165 is set within the formation 77, such as by curing cement 400 to hydrostatic pressure. The wire 240 is then coupled, preferably inductively coupled, to the wire 140 by any method known by those skilled in the art. When the wire 240 is coupled to the wire 140, information may be transferred to surface equipment 180 from downhole equipment 170, and to downhole equipment 170 from surface equipment 180. Further, downhole tools may be operated by signals sent to downhole equipment 170 from the surface 77. Subsequent casing strings (not shown) with earth removal members attached thereto and downhole equipment disposed thereon may be drilled into the formation in the same manner as described above while placing wire within a groove disposed within the casing strings. In this way, a cased wellbore may be formed of any desired depth within the formation.

[0075] An alternate embodiment of the present invention is shown in FIGS. 11-12. The parts of FIGS. 11-12 which are the same as the parts of FIGS. 1-7 are labeled with the same numbers. As shown in FIG. 11, the dispensing unit 190 is located above the rig floor 20. The wire 140 is run from the spool 183 through a hole 199 in the rig floor 20 and around the dispensing unit 190 for placement in the groove 111 of the first casing string 65. FIG. 12 illustrates the spider 60 usable with this embodiment. The spider 60 has gripping members 12 such as slips which grippingly engage the casing string 65 at various stages of the operation, as described above in relation to FIGS. 1-7. A gap 13 is disposed between the gripping members 12 so that the wire 140 may be run through the spider 60 without the gripping members 12 damaging the wire 140. The groove 111 is aligned with the gap 13 in the gripping members 12. Subsequent grooves 112, 121, and 122 are placed within the gap 13 in subsequent stages of the operation.

[0076] In all of the above embodiments, as shown in FIG. 13, the lower ends of the grooves 111, 121 of the casing strings 65, 30, and 15 may be enlarged. Likewise, the upper ends of the grooves 112, 122 of the casing couplings 96, 31, and 16 may be enlarged. Enlarging the mating portions of the grooves 111, 121, 112,122 allows the wire 140 to pass through the grooves 111, 121, 112, 122 even if the grooves 111, 112, 121, 122 are not exactly aligned. The grooves 111, 121, 112, 122 must only be substantially aligned.

[0077] The above embodiments of the invention are also contemplated to be utilized while drilling into the formation with the conventional completion method, namely drilling with a drill string into the formation to form a wellbore of a first depth, placing a first casing string into the wellbore of the first depth, then drilling to subsequent depths and placing subsequent casing strings within the wellbores of subsequent depths. The wire 140 is at least partially subflushed to the surface of the casing sections and couplings which make up a casing string by grooves formed in casing sections and couplings, as described above. The first casing string 65, in the conventional drilling method, would not possess an earth removal member at its lower end; rather, the first casing string 65 would be similar to the second casing string 30. The wire 140 is placed within the grooves of casing sections as described above while lowering the casing string 65 (and subsequently casing string 30) into the previously drilled wellbore. The method of timing threads, as described above, may be utilized to align the adjacent grooves of the casing couplings and casing sections so that the wire 140 is subflushed to the surface of the casing couplings and casing sections across threaded connections. It is also contemplated that any type of tubular body, not merely casing strings, may be utilized to at least partially subflush and protect the wire 140 across connections of tubulars.

[0078] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. 

1. A method of wiring casing while drilling with casing, comprising: lowering a first casing string with an earth removal member operatively connected to its lower end into an earth formation; and placing wire on the first casing string while lowering the first casing string.
 2. The method of claim 1, wherein the wire is at least partially sub-flushed to a surface of the first casing string.
 3. The method of claim 1, wherein the wire electrically connects surface equipment to downhole equipment.
 4. The method of claim 1, further comprising: connecting a second casing string to the first casing string; lowering the first casing string into the earth formation; and placing the wire on the second casing string while lowering the first casing string.
 5. The method of claim 4, wherein the wire is sub-flushed to a surface of the first casing string and the second casing string.
 6. The method of claim 4, wherein connecting the second casing string to the first casing string comprises substantially aligning a groove in the second casing string with a groove in the first casing string.
 7. The method of claim 6, wherein substantially aligning the grooves comprises substantially aligning an enlarged portion of the groove in the first casing string with an enlarged portion of the groove in the second casing string.
 8. The method of claim 6, wherein substantially aligning the groove in the second casing string with the groove in the first casing string comprises substantially aligning timing marks.
 9. The method of claim 8, wherein the first casing string and second casing string are pre-machined to substantially align the timing marks at a predetermined torque.
 10. The method of claim 1, wherein placing wire on the first casing string comprises dispensing the wire from a spool located below a rig floor while lowering the first casing string.
 11. The method of claim 1, wherein the wire is placed on the first casing string above the rig floor.
 12. The method of claim 1, further comprising monitoring conditions within the earth formation through the wire while lowering the first casing string.
 13. The method of claim 1, further comprising manipulating one or more downhole tools through the wire while lowering the first casing string.
 14. The method of claim 1, further comprising using the wire to sense a geophysical parameter while lowering the first casing string.
 15. The method of claim 1, wherein a sensing device is located at a lower end of the wire.
 16. The method of claim 1, further comprising: lowering the first casing string to a first depth within the earth formation; and operating one or more downhole tools through signals sent through the wire.
 17. The method of claim 16, wherein the one or more downhole tools comprises a cementing apparatus.
 18. The method of claim 16, wherein the one or more downhole tools comprises one or more packers.
 19. The method of claim 16, wherein the one or more downhole tools comprises one or more valves.
 20. A method of wiring casing while drilling with casing, comprising: lowering a first casing string with an earth removal member operatively connected to its lower end into an earth formation; placing a first wire on the first casing string while lowering the first casing string to a first depth within the formation; lowering a second casing string with an earth removal member operatively connected to its lower end into the formation; and placing a second wire on the second casing string while lowering the second casing string to a second depth within the formation.
 21. The method of claim 20, further comprising inductively coupling the first wire to the second wire.
 22. The method of claim 21, wherein the wire is substantially sub-flushed to a surface of the first casing string.
 23. The method of claim 21, wherein the first wire and the second wire electrically connect surface equipment to downhole equipment.
 24. The method of claim 23, wherein surface equipment is connected to the first wire and downhole equipment is connected to the second wire.
 25. The method of claim 20, wherein the first wire is dispensed from a first spool and the second wire is dispensed from a second spool.
 26. An apparatus for use in transmitting signals from within a wellbore to a surface of the wellbore, comprising: downhole equipment for sensing information from within the wellbore; surface equipment for processing the information; a wire for transmitting the information from the downhole equipment to the surface equipment; and a first casing string with an earth removal member operatively connected to its lower end, wherein the first casing string houses the wire.
 27. The apparatus of claim 26, wherein the downhole equipment comprises a sensor.
 28. The apparatus of claim 26, wherein the surface equipment comprises a processing unit.
 29. The apparatus of claim 26, further comprising a first casing coupling connected to an upper end of the first casing string, wherein the first casing coupling houses a portion of the wire above the first casing string.
 30. The apparatus of claim 26, wherein the wire is housed in a continuous groove formed within the first casing string and the first casing coupling.
 31. The apparatus of claim 30, wherein the continuous groove comprises an enlarged groove portion of the first casing string substantially aligned with an enlarged groove portion of the first casing coupling.
 32. A method for monitoring conditions within a wellbore by wiring casing, comprising: lowering a first casing section to a first depth within a formation; and placing wire on the first casing section while lowering the first casing section, wherein the wire is at least partially sub-flushed to a surface of the first casing section.
 33. The method of claim 32, wherein the wire electrically connects surface equipment to downhole equipment.
 34. The method of claim 32, further comprising: connecting the first casing section to a second casing section; lowering a second casing section to a second depth within the formation; and placing the wire on the second casing section while lowering the second casing section, wherein the wire is at least partially sub-flushed to a surface of the second casing section.
 35. The method of claim 34, wherein the wire is continuous across the connection of the first casing section to the second casing section.
 36. The method of claim 34, wherein the wire is continuously sub-flushed across the connection of the first casing section to the second casing section.
 37. An apparatus for use in transmitting signals from within a wellbore to a surface of the wellbore, comprising: downhole equipment for sensing information from within the wellbore; surface equipment for processing the information; a wire for transmitting the information from the downhole equipment to the surface equipment; and a first casing section comprising a groove therein for at least partially sub-flushing the wire to the surface of the first casing section.
 38. The apparatus of claim 37, further comprising a second casing section comprising a groove therein for at least partially sub-flushing the wire to the surface of the second casing section, wherein the second casing section is connected to the first casing section.
 39. The apparatus of claim 38, wherein the wire is continuously sub-flushed across the connection of the first casing section to the second casing section.
 40. The apparatus of claim 38, wherein the groove of the first casing section comprises an enlarged portion which connects to an enlarged portion of the groove of the second casing section.
 41. An apparatus for use in transmitting signals from within a wellbore to a surface of the wellbore, comprising: downhole equipment for sensing information from within the wellbore; surface equipment for processing the information; a wire for transmitting the information from the downhole equipment to the surface equipment; a first tubular comprising a groove therein for at least partially subflushing the wire to a surface of the first tubular; and a second tubular comprising a groove therein for at least partially subflushing the wire to a surface of the second tubular, wherein the first tubular is connected to the second tubular and the wire is sub-flushed across the connection.
 42. A method for monitoring conditions within a wellbore while lowering tubulars into the wellbore, comprising: lowering a first tubular into the wellbore; placing wire on the first tubular while lowering the first tubular, wherein the wire is at least partially sub-flushed to a surface of the first tubular; connecting the first tubular to a second tubular; lowering the second tubular into the wellbore; and placing wire on the second tubular while lowering the second tubular, wherein the wire is at least partially sub-flushed to a surface of the second tubular, wherein the wire is sub-flushed across the connection of the first tubular to the second tubular. 